The present invention relates to containers and in particular to improvements in a form, fill and seal container forming apparatus.
U.S. patent application Ser. No. 09/216,607, the contents of which are incorporated herein by reference, discloses a form, fill and seal container forming apparatus. The apparatus includes a container forming station having a heat sealing and cutting mechanism and a backing plate. The heat sealing and cutting mechanism and backing plate are moveable towards one another to trap a fluid-filled tube therebetween. Once trapped, transverse heat seals an formed across the fluid-filled tube and the tube is cut between the heat seals to form an individual, fluid-filled container. In order to ensure adequate seals are formed, the heat sealing and cutting mechanism and the, backing plate both include aligned heat sealing wires.
During formation of the heat seals, the heat sealing and cutting mechanism and the backing plate are brought together to trap the tube. The heat sealing wires are then energized to form closely spaced heat seals across the tube. Once the heat seals have been formed, a centrally disposed resistive wire on the heat sealing and cutting mechanism is energized to cut the tube between the heat seals thereby to separate the container from the tube. Although this design results in high integrity seals, it has been found that the heat sealing wires on the heat sealing and cutting mechanism and backing plate burn the packaging material in some instances making the containers unsightly. Also, due to the proximity of the heat sealing wires to the centrally disposed resistive wire, insufficient room is provided to overlie the heat sea ling wires with Teflon(trademark) tape. Also, when the centrally disposed resistive wire is energized and expands, it has been found that in some instances, the resistive wire moves and contacts one of the heat sealing wires.
Also, in this container forming apparatus, as the containers are formed and separated from the tube, they fall under the influence of gravity into a diverter. The diverter is configured to orient the packages so that they are delivered to a carrier in a desired orientation. Unfortunately, because of the flexibility of the containers and the fact that successive containers fall from the tube at different heights, the containers often rotate by different amounts before reaching the diverter. As a result, the containers contact the diverter differently resulting in differently deformed pouches being received by the carrier. This of course makes it difficult for downstream, equipment to handle the individual containers. As a result, the containers must be reoriented on the carriers to allow the downstream equipment to act on them properly.
It is therefore an object of the present invention to provide improvements to a form, fill and seal container forming apparatus.
According to one aspect of the present invention, there is provided a heat sealing and cutting station for a container forming apparatus to form heat seals and cuts across a fluid-filled tube of flexible packaging material at longitudinally spaced locations, said heat sealing and cutting station comprising:
a cutting mechanism including a carrier accommodating a resistive wire energizeable to cut said tube when said carrier is in contact with said tube;
a heat sealing mechanism on an opposite side of said tube and being aligned with said carrier, said heat sealing mechanism including a support carrying a pair of resistive bands energizeable to form closely spaced heat seals across said tube when said heat sealing mechanism is in contact with said tube;
a drive operable on said cutting mechanism and said sealing mechanism to move said cutting mechanism and said heat sealing mechanism between retracted positions where the tube is free and extended positions where said tube is trapped between said cutting and sealing mechanisms, said carrier further including tracks extending forwardly thereof and generally matching the shape of said resistive bands; and
power supply means to energize said resistive bands and said resistive wire.
According to another aspect of the present invention, there is provided a heat sealing and cutting station for a container forming apparatus to form heat seals and cuts across a fluid-filled tube of flexible packaging material at longitudinally spaced locations, said heat sealing and cutting station comprising:
at least one set of jaws moveable between a fully open position where said tube is free and a closed position where said tube is trapped between said jaws;
a heat sealing mechanism carried by said jaws to form a heat seal across the tube when said jaws are in said closed position;
a cutting mechanism carried by the jaws to cut the tube along the heat seal when the jaws are in the closed position to separate a container from the end of the tube; and
a container holding mechanism carried by the jaws, said container holding mechanism holding said container when said jaws begin moving from the closed position towards the fully open position in a manner to allow the container to rotate and take a desired orientation before said container is released.